The "request" dependency is deprecated. An updated example is required.

On [this](https://github.com/fbsamples/messenger-platform-samples/blob/0cfefe3e8121defe44e55303effe106e9e983356/quick-start/app.js#L185) line, the call to `request` package is made. Which according to their official [npm registry](https://www.npmjs.com/package/request) is deprecated.

One of the [suggested alternatives](https://github.com/request/request/issues/3143) is [`node-fetch`](https://www.npmjs.com/package/node-fetch) package.